Nonlaying, molting hens and laying hens will be injected intraventricularly with either LH-RH or progesterone and the increase in plasma LH and progesterone will be measured. Progesterone will be injected intraventricularly at 20-22 h prior to ovulation and the change in plasma LH and progesterone and the incidence of premature ovulation will be measured. If as we suspect LH will rise, but progesterone does not then we will inject progesterone into the largest follicle to determine whether progesterone is required at the level of the ovary. We will pursue further whether antibodies to progesterone are capable of preventing ovulation, so far we have not been successful in achieving such inhibition of ovulation.